Vorwahl

Vorwahl is the sequence of digits at the beginning of a telephone number that designates a geographic area or a service type within a national numbering plan. It helps to route calls to the correct network or region and can be used for both landline and mobile numbers, as well as certain special services. The concept exists in many countries, with country-specific formats and lengths.

In Germany, the Vorwahl typically includes a leading trunk zero when dialing domestically. For example, calling Berlin uses 030, where 0 is the trunk prefix and 30 is the area code. The remaining digits form the subscriber number. When calling from abroad, the leading zero is omitted and the country code is used instead (for Germany, +49). Thus a Berlin number becomes +49 30 followed by the subscriber number.

There are several common types of Vorwahlen. Geographic or Ortsvorwahl refers to the area code of a city or region. Mobile numbers have prefixes that identify the mobile network or service region. In addition, there are service or special-purpose Vorwahlen, such as toll-free numbers that begin with prefixes like 0800 or 0800x, and other paid services with 018x or 090x prefixes. The length and structure of Vorwahlen vary by country and are defined by national or regional numbering plans.

In practice, the Vorwahl is an essential element of dialing and number portability, influencing how numbers are presented, stored, and dialed, both domestically and internationally. It complements the subscriber number to form a complete telephone address.